Wiring board design support apparatus, method for wiring board via arrangement and storage medium recording program for wiring board via arrangement

1. A wiring board design support apparatus arranging a plurality of vias on a wiring board, comprising: a design information storage unit that stores design information of vias and wirings to be arranged on the wiring board; and a wiring board via arrangement unit that moves, on a basis of the design information, positions of lattice points arranged with same intervals in both a vertical direction and a horizontal direction by a given moving amount in the vertical direction and the horizontal direction while alternately changing a moving direction in the horizontal direction of the lattice points for each row of the lattice and alternately changing a moving direction in the vertical direction of the lattice points for each column of the lattice, so as to arrange vias at positions of the lattice points after movement, wherein the wiring board via arrangement unit includes: an excess clearance calculation unit that calculates a value of an excess clearance when a wiring is arranged between vias that are located at positions of lattice points with equal intervals in the vertical and horizontal directions, an insufficient clearance calculation unit that calculates a value of an insufficient clearance when a number of wirings arranged between the vias is increased, a moving amount calculation unit that calculates the given moving amount based on the excess clearance value and the insufficient clearance value, and wherein the wiring board via arrangement unit alternately moves the lattice points by the given amount in each of the vertical and horizontal directions to: reduce the excess clearance between the wiring and vias located at positions of lattice points adjacent the wiring, and provide sufficient clearance between the increased number of wirings and positions of lattice points adjacent the increased number of wirings, whereby a resulting pitch of the lattice points after said movements is unequal so as to alternately accommodate different numbers of wirings between adjacent vias in the horizontal and vertical directions.

2. The wiring board design support apparatus according to claim 1 , wherein the moving amount calculation unit calculates the given moving amount for moving the positions of the lattice points in the vertical direction and the horizontal direction in accordance with a comparison result between the value of the excess clearance and the value of the insufficient clearance.

3. The wiring board design support apparatus according to claim 1 , further comprising a wiring setting unit that sets a wiring between the vias in via arrangement made by the wiring board via arrangement unit.

4. A method for wiring board via arrangement for arranging a plurality of vias on a wiring board, comprising: storing, by a design information storage unit, design information of vias and wirings to be arranged on the wiring board; calculating a value of an excess clearance when a wiring is arranged between vias that are arranged at positions of lattice points with equal intervals in the vertical and horizontal directions, calculating a value of an insufficient clearance when a number of wirings arranged between the vias is increased; and moving, by a wiring board via arrangement unit, on a basis of the design information, positions of lattice points arranged with same intervals in vertical and horizontal directions by a given moving amount in both a vertical direction and a horizontal direction, wherein a moving direction of the lattice points is alternately changed in the horizontal direction of the lattice points for each row of the lattice and alternately changed in the vertical direction of the lattice points for each column of the lattice, so as to: reduce the excess clearance between the wiring and vias arranged at positions of the lattice points adjacent the wiring, and provide sufficient clearance between the increased number of wirings and vias located at positions of the lattice points adjacent the increased number of wirings, and whereby a resulting pitch of the lattice points after said movements is unequal so as to alternately accommodate different numbers of wirings between adjacent vias in the horizontal and vertical directions.

5. A recording medium readable by a computer storing a program for wiring board via arrangement, the computer comprising: a design information storage unit that stores design information of vias and wirings to be arranged on a wiring board; and a wiring board via arrangement unit that moves, on a basis of the design information, positions of lattice points arranged with same intervals in both a vertical direction and a horizontal direction by a given moving amount in the vertical direction and the horizontal direction while alternately changing a moving direction in the horizontal direction of the lattice points for each row of the lattice and alternately changing a moving direction in the vertical direction of the lattice points for each column of the lattice, so as to arrange vias at positions of the lattice points after movement, wherein the wiring board via arrangement unit includes: an excess clearance calculation unit that calculates a value of an excess clearance when a wiring is arranged between vias that are located at positions of lattice points with equal intervals in the vertical and horizontal directions, an insufficient clearance calculation unit that calculates a value of an insufficient clearance when a number of wirings arranged between the vias is increased, a moving amount calculation unit that calculates the given moving amount based on the excess clearance value and the insufficient clearance value, and wherein the wiring board via arrangement unit alternately moves the lattice points by the given amount in each of the vertical and horizontal directions to: reduce the excess clearance between the wiring and vias located at positions of lattice points adjacent the wiring, and provide sufficient clearance between the increased number of wirings and positions of lattice points adjacent the increased number of wirings, whereby a resulting pitch of the lattice points after said movements is unequal so as to alternately accommodate different numbers of wirings between adjacent vias in the horizontal and vertical directions.

6. The wiring board design support apparatus according to claim 5 , further comprising a wiring setting unit that sets a wiring between the vias in via arrangement made by the wiring board via arrangement unit.